During a visit to Germany, Premier Li Keqiang said on Thursday that China would “steadfastly” implement the Paris climate deal even if the US pulled out.

“China will continue to implement promises made in the Paris Agreement, to move towards the 2030 goal step by step, steadfastly,” Li said in a joint press conference with German Chancellor Angela Merkel. “But of course, we also hope to do this in cooperation with others.”

Merkel said Germany and China should work closely together on issues such as protecting the climate.

Li’s remarks came as China and the EU were expected to reaffirm their climate commitments under the Paris pact in a joint statement on Friday, sending a clear message if Trump does withdraw from the 195-nation deal – his decision is also expected to be announced on Friday.

Climate experts said Li’s remarks showed Beijing was keenly aware of the possible far-reaching impact of an American withdrawal from the Paris climate accord on the existing global geopolitical order.

Trump is widely believed to be leaning towards pulling the US out of the Paris agreement – seen as one of the most important accomplishments of his predecessor Barack Obama, who secured Beijing’s endorsement after years of negotiations.

Experts say that while the US move is expected to have profound implications for the international effort tackling climate change and would deal a major blow to Washington’s global standing, it has presented China with an unprecedented opportunity to emerge as a global leader on climate issues.

Li Shuo, a climate campaigner with Greenpeace China, said a Trump decision to retreat from the Paris climate deal would “no doubt leave a big hole in the international climate regime”, which would have to be filled by other key players, particularly China.

“While the US is apparently not ready [to tackle climate change, which] affects every nation, the rest of the world will not wait for Washington. In fact, there is no better time for China to further its international climate leadership,” he said.

China has surpassed the US to become the world’s top emitter of carbon dioxide in recent years. Beijing and Washington were widely seen as playing a key role in securing the Paris deal.

Li Shuo and other environmental experts said China’s commitment to the Paris deal was driven primarily by domestic concerns over the huge environmental and social cost of dirty coal and air pollution.

While China is on track to hit its 2030 emissions reduction targets – which would see the world’s biggest polluter cut emissions per unit of GDP by 60 to 65 per cent by 2030 from its 2005 level – Beijing has also pledged to help poorer nations combat climate change. That includes a 2015 commitment of a US$3.1 billion climate fund.

Zhang Haibin, a climate diplomacy expert at Peking University, said China was expected to join the EU and other developing economies to fill the leadership vacuum left by the US.

“It is not realistic to expect China to act alone or become a world leader on this issue because it is far beyond China’s capability. It has to be a shared leadership with other nations,” Zhang said.

He added that while the Paris deal would not collapse just because of Trump’s withdrawal, the US move would create uncertainties for its implementation and set a bad example for developing nations such as India and Pakistan, which are unwilling to fully commit to the deal.

It would also deal a heavy blow to the hard-won international consensus on tackling global warming and incur “substantial” additional costs for other key emitters, such as China and the EU, to fulfill their emissions reduction obligations under the Paris deal, he said.

Beijing would also encounter more resistance at home to its efforts to curb energy-intensive industries and greenhouse gas emissions if the US withdrew from the pact, according to Zou Ji, a former Chinese climate negotiator.

“But in the long run, it will underline the growing importance of developing nations, such as China, and force China to take on greater international responsibilities. As long as China can stand firm alongside the EU, the impact of the US retreat can be managed,” Zou said.

Li Shuo noted that China had undergone a remarkable transformation in the past decade – from climate spoiler at the 2009 Copenhagen summit, to a somewhat reluctant, cautious leader in the run-up to the 2015 Paris conference, to actively embracing the concept of climate leadership in the Trump era.

Xie Zhenhua, China’s special representative on climate change, said in January, just days before Trump was sworn in as the new US president, that China was already “capable of taking a leadership role” in the global campaign against climate change.